Protecting apparatus for presses and the like



Sept. 24, 1929. E. GUINOT 1,723,994

PROTECTING APPARATUSFOR PREssEs AND THE LIKE Filed April 19, 1927 4Sheets-Sheet 1 +8 5 LA 0 +3 j F 4-4 7? I 5 I L l 6 5 $3 E949 3' v 34- 3jas I 2 Q 0: 0

E. GUINOT Sept. 24, 1929.

PROTECTING APPARATUS FOR PRESSES AND THE LIKE Fi1ed.April 19, 1927 4Sheets-$heet 2 Sept. 24, 1929. E .GU|NQT 1,728,994

PROTECTING APPARATUS FOR PRESSES AND THE LIKE Filed April 19. 1927 4Sheets-Sheet 3 x/vvewraa Sept. 24, 1929. E, GUINOT 1,728,994

PROTECTING APPARATUS FOR PRESSES AND THE LIKE Filed April 19, 1927 4Shets-Sheet 4 00 O O C) Patented Sept. 24, 1929 1 UNITED STATES:

PATENT, OFFICE;

EMILE QT, or rams," FRANCE PROTECTING APPARATUS FOR PRESSES AND THE LIKEApplication filed April, 19, 1927,.Seria1 No. 185,006, and in FranceApril 19, 1926.

Numerous apparatuses are already known for protecting the hands duringoperation on presses, machine-tools and the like, but these apparatuses,whether theycomprise a shut- 5 ter with a hand, guard, or whether theyare based on a clutch actuated with both hands, are either of a verylittle protection,or of such a construction that it is difficult toadopt them on the different types of machines, or again theyconsiderably hinder the work of the op erator and thus diminishtheproduction- The same is true for apparatus comprising a rockingshield coming in front of the tool as the pedal operates the saidshield,

.3 as it often happens that the workman, to

gain time, withdraws his foot from the pedal 7 immediately afterhe hasthrown the machine in gear. In this case, the shield is withdrawn beforethe punch has effectedv its 2:) operation.

On the other hand, a safety device auto-v matically throwing the machineout of gear after each stroke, when the foot would be pressing on thepedal, is not efficient and iii must, for protecting the workmens hands,

he completed by a special protecting apparatus. p a

Finally, when the protector is positively connected to the pedal, therapid descent of the protector can inflict injury to the workmanaccording to the energy of the pressure of the foot on the pedal. 1 a aThe present invention is adapted to do away with or attenuate the abovementioned a; inconveniences and hasfor an object a protecting apparatusforpresses, machine tools and the like, in which the throwing in gearcannot take'place until the fingers of the workman are outside thevicinity. ofthe tool 401-ior out of reach of the dangerous movableparts.

In the apparatus hereinafter described, the protecting shield descendsrapidly by its own weight (the oint being perfectly oiled),

which movement cannot harm the workman, and the'apparatus'is providedwith a safety device, so that the protecting, shield protects theworkman for'the entire duration of the work operation of the machine, asit is only at the end of the stroke that the showing the safety device.

apparatus can return to its initial position.

The apparatus forming the subject-matter of the present invention isconstituted principally by: a rocking control lever having areturnspring, one arm of the said lever 5.1; having an adjustableabutment screw and the other arm being terminated by a finger forming astop piece; a rocking: camprovided with a stop tooth and an abutmentarm, the said cam being controlled by the said lever or wedging it toensure protection and both of which are enclosed ina box arranged ina'suitableplace on the frame; one or two levers fixed outside the box onthe axis of the cam and carrying rods adjustable with the protectingshield a double lever fixed on the axis of the control lever andconnected on one side to the looking I clutch memberof the machine by alink having an oblong openingor lost motion slide and, on the otherside,-by a rod adjust-able in position by the control of the clutch; and

- if necessary a safety device locking the protectingaplparatus when theshield has moved down to t e full extent of itsstroke and releasing thesaid apparatus by taking the control on the dangerous movable part ofthe machine when the protecting shield can be raised without any dangerfor the work- .mans hands.

The invention is described hereinafter in drawing which shows by way ofexample two forms of construction oft-he protecting 85,; apparatus, withsupplementary safety device, constructed according to the principlespecified and applied to a press.

'Fig. 1 illustrates in elevation, the protecting apparatus, with thecover enclosing the control lever and the cam, removed, and also Fig. 2is a plan View of the apparatus illustrated in Fig. 1.

Fig. 3 is a cross sectional View of a part of the apparatus shown'inFig. 1.

Fig. 4 is an elevation of the box without the lid and without the safetydevice.

Fig. 5 is an elevation of the box Without the lid, but with the innerparts, in position when the machine is thrown in gear'and with thesafety device in action.

Fig. 6 shows corresponding positions of the rocking control lever and ofthe driven cam permitting the operation of the machine.

Fig. 7 shows the corresponding position of the sameparts when the handsor any other obstacle prevent the protecting shield from moving down tothe entire extent of its movement and thus preventing the throwing ingear and the operation of the machine.

Fig. 8 is a side elevation of the modification of the apparatus.

Fig. 9 shows the arrangement of the cams within the box.

Fig. 10 is a plan view of the apparatus shown in Fig. 8.

Fig. 11 shows a press, partly in section, provided with a supplementarysafety device fitting on the protectingapparatus, particularly forslow-running presses.

In the drawing, 1 indicates the box secured in a suitable place on themachine by lugs 2 and closed by a lid 3 and screws 4.

On an axis 5, which is journalled and rocks in the box and the lid, issecured acontrol lever 6, an arm of which, slotted at 7 for the passageof the clamping screw 8, carries an adjustable abutment 9, and the otherarm of which is terminated by a finger 10 forming a stop piece, the'saidlever being constantlysubjected to the action of a returning spring 11secured at 12 to the box and at 13 to a pin onthe lever.

On another axis 14, also rocking in the box and." the lid, is secured. acam 15 having a st'optooth 16 with a notch and an abutment arm 17, thesaid cam being in relation with and controlled by the lever 6 by whichit is locked, in case of an ohslacle'preventing the protecting shieldfrom moving down to the full extent of its stroke.

On the axis 14, which extends through the lid aflm-e is secured, by acone for regulating its orientation, a lever 18 wlth cone bearingstherel'ietween to permit varying their relative position with a rod 19adjustably positioned as at 20 and carrying a protecting shield 21,perforated for permitting observation of the tool.

The axis 14 can be connected, across the frame, by anextension in theshape of a tube 22, to another stub shaft 23 journalled' in a support 24secured to the frame 25 of the machine.

This stub shaft 23 is provided with a lever 26 having a rod 27adjustably positioned as at 28 for supporting on the other side theprotecting shield 21.

It is obvious that the axis 14 need not be extended and the protectingshield 21 can be held by one lever 18 alone.

The protecting shield by its own weight,

tends to descend and to cause'the arm 17 to follow the'abutment 9 of thelever 6 to keep itself in contact with the latter.

The rocking of the levers 18 and 26 is regulated so that the protectingshield 21 is stopped in its downward movement and by means hereinafterdescribed prevents the throwing into gear of the machine when theworkmans hand are still in the danger zone of the tool or in thevicinity of the movable parts. The movement of the levers 18 and 26,either by abutments 29 30 or by abutments secured on the tool, whichstop the shield, or in any other suitable manner and they are adjustablysecured on'the axis 14 so that, at the lower position of the shield, thetooth 16 of the cam 15 disengages the nose or finger 10 of the lever 6so as to per mit the latter to continue its'stroke.

On the axis 5 and in front of the lid 3 is secured, also by a conicalpart, a double lever 31, the upper eye 32 of which is connected to theclutch locking members of the machine by a link 33 having an oblongopening 34. whilst the lower eye 35 is connected to the startingcontrol, handle or pedal, by a rod 36 adjustable in position by a screw37.

The length of the' oblong opening will be determined according to therocking'of the shield and the idle stroke of the link is taken on thestroke of the pedal and so to'speak without effort;

The box 1 carries a boss 38in which moves a locking rod or safety bolt39 constantly pressed, by a spring 40 of a housing 41', against thelever 6 provided with a notch 42 to receive thesaid safety bolt 39 andto'thus lock theapparat'us. I

The locking rod 39 is terminated by a stop 43 in contact with the arm 44of the bell crank lever, rocking on the axis 45 of a support 46projecting from thebox 1.

The second arm 47 of the bell crank lever carries an adjustableextension 48 with an abutment 49 also adjustable, capable of placingitself under the slide or any other part or extension of the slide-block50 of a press or under the dangerous movable part of a machine.

The operation of the machine is as follows: When the machine is at rest,the parts occupy the positions illustrated in Figs. 1,2,

3 and 4, that is to say the protecting shield 21' is in its uppermostposition and clears the tool, the lever 18 rests against the abutment 29and the returning spring 11 acting on the lever 6, raises the doublelever 31 and maintains thecontact of the abutment 9 with the arms 17 Assoon as the starting rod 36is operated, by drawing it downwardly,theaxis 5 rocks under the action of the returning spring 11, the doublelever 31, moves down, drawing with it the link 33, whilstlthe arm of thelever 6 carrying the abutment 9 rises and releases the arm 17 of the cam15.

The protecting shield 21, acting by its own weight causes the axis 14to. rock and, with it,

that is to say that no part whateveror hands are in the dangerous zoneor in the vicinity of the tool, it is from thls moment only that theactuation of the clutch can begin to take I place. y

- The throwing in gear commences at'the precise moment the lever 6 andcam 15 reach the position shown in Fig. 6, that is to say. that the noseof the lever 6 passes beyond the tooth 16 and can become engaged intothe notch of the cam 15.

At this moment and during the actuation of the clutch, the lev'cr 6continues its rocking movement and the cam stopping, the

nose 19 enters farther and farther into the notch, so that at the end ofthe throwing'in gear theparts will take the position shown in It will benoted that at the very moment the lever 6 and the cam 15 take theposition shown in Fig. 5, the safety device will begin to act, that isto say the bolt 39 pressed by the spring 40, will enter the notch 42 ofthe lever 6 and will lock the protecting appa ratus, thus preventing theshield 21 to rise before the slide-block has accomplished its operationor its entire down stroke.

In these conditions, if the-slide-block 50, or the dangerous part of themachine stops during the operation, the protecting shield 21 is helddown and prevents the workman from placing his hands in the dangerouszone before proceeding to a new actuation of the clutch producing thecomplete descent of the slide-block.

It will be seen, therefore,.that. t his safety device is particularlyuseful and efficient in I case the workman removes his foot from thepedal too rapidly and that the shield rises before the punch haseffected its work, or again,

when the slide-block stops during itsmovement.

In fact, when the slide-block 50 reaches the end of its stroke, itacts,a short time be-, fore, on the abutment 49 by lowering the extension48with the-arm 47 of thebell crank lever, the other arm 44 of which actson the. I stop 43, forces the bolt 39 out of the notch 42 against thestress of the spring 40, and re-' leases the lever 6, thus permittingthe operation of the protecting shield and the raising of the protectingshield, without danger for,

the workmans hands. I

It is obviousthat the latching up of the main control lever 6 can beeffected by: all other means suitable to the machine and that, incertain cases, especially with'high speed I machines having a smallstroke, the safety device could be done away with and renderedinoperative as then, during the automatic operationof the machine, theshield usually remains in protecting position and rises only at the timethe machine stops.

On the contrary, if the protecting shield does not completely fall. toits lowermost position andstops on the way because one hand of theworkman is belated and still remains in the dangerous zone, thuspreventing the free and complete descent of the said protecting shield,the arm 17 will not follow the abutment 9, the finger 10 of lever 6 willabut against the outer surface of the cam 15 and these members will takethe position shown in Fi 7.

It will be seen that in this latter position, the lever 6 cannotcontinue to rock and to move downwards in order to be able to actu-l atethe clutch device, the machine will not operate notwithstanding theaction on the link 36 controlling the starting of the machine. g I

We shall now suppose that the apparatus is applied to a pedal press.

When the slide-block has risen and that the starting pedal has beenreleased, themachine stops at (the top of its stroke and .the protectingshield comes back into its uppermost position, under the action of thereturning spring.

In these conditions, three cases can occur:

1.The press is provided with a safety clutch.

Int-his case, the slide-block is automatically unclutched at each end ofits'stroke, even when the pressure on thepedal is maintained. i T

In these conditions, the pedal must be abandoned and a new pressure mustbe exerted on this pedal for reclutching and the protecting apparatusthen comes back to its starting position.

2..The press is not provided with a safety clutch. V

In this case, as long as the foot presses on the pedal, the presscontinues to work.

protecting device does not present any inconvenience, since the shieldis always in its lowermost position during the time a pressure isexerted'on the pedal and it rises only when the latter is abandoned. 1'3.The press can be provided with the safety clutch or with the ordinaryclutch.

Let us suppose that the operator immediately removes his foot from thepedal as soon as he has thrown the machine in gear: In these conditions,with the safety device of theapparatus, the protecting shield remainsin. position until the tripping action occurs at'the end of the strokewhichcauses the shield to come back to-its starting point. The form ofconstruction of the modified apparatus illustrated in Figs. 8, 9, 10shows the adjustment devices and various' arrangements of the parts forensuring the protection and for renderingthe' apparatus more easilyapplicable to the various machines.

In fact in the improved apparatus hereinafter described, the extremepositions of the cams and, consequently, those of the protecting shieldare adjusted from the exterior and the apparatus comprisesvariousadjusting devices to compensate for the variations of the strokesand of the heights of the tools; to this apparatus can be adapted asupple mentary device,"very useful in certain cases, for increasing thesecurity and efiiciency of protection.

operating lever 31, the lower cam 15' is mounted on the axis 14:carrying the lever 18.

The lever 31 is connected, on the onehand, to the pedal by theadjustable rod 36 and, on the other hand, to the clutch control by therod 33.

The connection of the rod or link 33 with the lever 31 is not rigid, therod slides in a yoke 52 and its stroke is adjustable.

The stroke of the protecting shield is limited at the top by theabutment s'crew53 and at the bottom by the abutment screw 54.

The latter is usually adjusted during the assemblage whilst the abutmentscrew 53 can be adjusted according to the press requirements for causingthe angle of oscillation of the shield to vary.

The adjustment of both cams 6 and 15'. is such that when the cam15 is incontact with the abutment .54, the nose 10 of the cam 6 can enterwithout play into the notch formed in the cam The spring has no actionwhatever on the operation of the shield, it is simply adapted tomaintain the connection between both cams 6 and 15' and to avoid theshocks which would alter the profile of the latter the noses 9', 10 and16 can obviously be adjusted by means of screws or otherwise.

' It will be understood that the cams can be replaced by leversprovidedwith holes or notches and abutments, adjustable or not, or bysimilar means and according to the Pup'ose sought for.

The operation of this device is similar to that previously described. 7

In the position of rest, the lever 18 of the cam 15 bears upon theabutment 52, the noses 10' and 16' are completely released and the nose9' of the cam 6 presses upon the cam 15 for holdingthe shield 21 inposition at the top of its stroke.

'As soon as the pedal is pressed upon, the operating lever 31 drives thecam 6', this causing the contact between cam 15 and cam 6 to cease,contact which was maintained by the action of the weight of the shield21 and of the levers. V

When the shield 21 has effected its entire rocking movement, that is tosay when the cam 15 is-in contact with the abutment 54, the cam 6 canstill continue its oscillation and the nose 10 of the cam 6 can enterthe notch of the'cam 15. I

The abutment nut 56, secured on the link 33 is so adjusted that when thenose 10 of the cam 6 is opposite thenose 16 of cam 15, a slightclearance remains between the nut 56 and the yoke 52.

By continuing to press upon the pedal,'the link 33 is moved and theclutching action takes place in. the same Way as described in thepreceding example.

If, accidentally, the shield cannot accomplish its full rockingmovement,eitherbecause the workman has not removed his hand from the tool, orbecause any m'emberis eng'aged on the die, the cam 6 abuts on thecircular portion of the cam 15' and thus cannot continue its rockingmovement that is to say although the workman presses upon the pedal, thelatter remains stationary} It frequently happens that, for the purposeof gaining time, the workmen operating the presses are accustomed toremove the foot from the pedal as soon as the throwing in gear has takenplace; this rapid operation has no inconvenience in the case ofpressesprovided with a flywheel, but might have inconvenience with presseshaving gearsand a long stroke, that is to say slow-running presses.

In fact, as soon as the workman releases the pedal, the protectingapparatus takes back its initial position and the shield rise-s; thenitmight happen that the rising of the shield might take place before theslideblock hasentirely effected its down stroke.

Thus, for ensuring an absolutely efficient protection in' the case ofpresses provided with eccentrics, gears and having a long stroke, usecan be made of the following safety device (see Fig. 11).

[A lever 57 is fitted on theaxis 22 of the shield-carryingjlever. thislever being provided at the front with a rectangular mortice 58 forpermitting the passage of arocking bolt 59 having a stop projection 60on the other hand, onthe slide-block 50 of the press isI securedanadjustable abutment 61.

The operation of the apparatus is then as follows:

When the shield 21 arrives at the bottom of its stroke the rocking lever59 looks the lever 57, so that when the workman releases the pedalbefore the slide-block 50 has effected its up stroke, the said lever 57cannot rise and it is only when the slide-block 50 arrives at the end ofits stroke that the abutment 61 acts upon lever 59 for releasing thelever 57, and the protecting shield can re-take its up per initialposition.

The protecting apparatus modified as above described can be fitted onall types of presses and comprises all the adjusting devices forcompensating the variations of strokes and height of tools.

Thus, it can be applied very easily on all eccentric presses.

The protecting shield, instead of being positively actuated during thedownward movement by the clutch pedal (which has the inconvenience ofhurting the operators) descends by its own weight and the levers onwhich it is secured are balanced by a counterweight 62 so that thedownward movement should not be too rapid, so that the workman cansupport the shock of the shield without being inconvenienced.

On the contrary, the rising of the shield is positively ensured by therising movement of the pedal. I

The shield can be very easily adjusted in all the positions; it can bemoved towards or from the center of the slide-block, and the angle ofoscillation can be adjusted according to the requirements. 1

The shield can be adjusted for permanently occupying a position forensuring protection when the tool operates in a continuous manner, as itsufiices to adjust the abutment 58 accordingly for obtaining a lockingaction. I

The operation of the apparatus is absolutely safe and takes placewithout the help of any spring.

Vfhat I claim as my invention and desire to secure by Letters Patentis 1. A protecting apparatus for presses and machine tools having aclutch and a clutch operating pedal, comprising a box mounted on themachine, a shaft having bearings in the walls of said box and projectedbeyond a side thereof, a rocking operating lever mounted on said shaftwithin the box, a spring for returning said shaft to a normal position,one arm of said lever being provided with an adjustable abutment and theother arm terminating in a finger, a second shaft having bearings in thewalls of said box and projecting beyond the walls thereof, a rocking camlever mounted on said second shaft within the box having an abutment anda stop tooth, the said levers lying in the same plane, the abutment armof said levers adapted to engage each other in one operative position,and the finger on the operating lever adapted to engage the stop toothtion, a link secured on the shaft to which the cam lever is securedoutside the box, a protecting shield secured to said link, a doublelever secured on the shaft to which operating lever is secured and meansfor connecting one arm of said lever to the clutch of the machine, suchconnecting means comprising a lost-motionconnection, and means forconnecting the other arm of said lever to the clutch operating pedal.

2. The protecting apparatus according to claim 1 in which the finger ofthe operating lever is adapted to engage the tooth of the cam lever tolock the cam lever against return movement until it has completed a fullmovement in one direction. 1

3. A protecting device according to claim 1 and in combination therewithof a member adapted to lie in the path of a movable part of the machineand means operated by said operating lever to remove said member fromthe path of said movable part in a last period of movement of saidlever.

' 4:. A protecting device according to claim 1 and in combinationtherewith of a member adapted to lie in the path of a movable part ofthe machine and means operated by said operating lever to remove saidmember from the path of said movable part in alast period of movement ofsaid lever, said means comprising a movable rod and an abutment on saidlever normally out of engagement ant adapted upon movement of the leverto engage therewith.

In testimony whereof I have signed my name to this specification.

EMILE GUINOT.

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